I agree with the sophisticated points that Tyler makes above regarding free trade. The more basic point, however, is that contra Paul Craig Roberts and Charles Schumer, the theory of free trade does not rely on factor immobility. In fact, the theory shows that free trade and factor mobility have similar effects. Free trade in commodities tends to create factor-price equalization – i.e. the same prices for wages and capital of equal productivity everywhere in the world even when the factors themselves are immobile. But factor price equalization is exactly what would be produced by factor mobility. You can be against free trade or be for it but being against the theory in one form and against it in another is just wrong.